Cholelithiasis in adult bearded dragons: retrospective study of nine adult bearded dragons (Pogona vitticeps) with cholelithiasis between 2013 and 2015 in southern Germany
With an increasing interest in pet reptiles and with so many reptile species available on the market, the care necessary for each individual species is directly related to most of the problems seen with pet reptiles (Stahl, 2003). Currently, reptile diseases still are mostly associated with poor husbandry, such as inadequate housing or nutrition (McWilliams, 2005; Wright, 2008; Köhler et al., 2013). To simplify nutritional assessment and requirements for reptiles, they are traditionally grouped into three categories: carnivores, herbivores and omnivores. There are, however, species like the bearded dragon (Pogona vitticeps) that are considered omnivorous (50% insects, 50% greens) when juvenile and herbivorous (90% greens, 10% insects) when adult (MacMillan et al., 1989). This requires a transition of diet after roughly 1 year of age, when the animals reach sexual maturity. This fact is unknown to many owners and pet retailers, so they continue to feed mainly insect‐based diets to adult bearded dragons. Imbalanced diets and poor feeding management frequently lead to nutritional disease in captive reptiles, especially when the diet is inadequate for the species or is not adjusted to the age of the animal.
Choleliths have been described in bearded dragons previously; however, neither stone composition analysis has been discussed nor the diet of the animal taken into account (Ritzman et al., 2009). Choleliths are divided into different classes according to their composition, and three main components have been identified in human medicine: cholesterol, calcium phosphate salts and bilirubin (Channa et al., 2007). Therefore, identifying the cholelith composition gives insights into its formation aetiology. Choleliths have been described in many species such as African elephant (Agnew et al., 2005), non‐human primate (Smith et al., 2006), deer mouse (Ginnett et al., 2003) and prairie dog (Brenneman et al., 1972), all with different cholelith compositions. In some cases, a nidus (or core) must be present for the formation of choleliths. This nidus allows, for example, minerals to attach and eventually form a stone. The aim of this study was to determine a cause for cholelith formation by accumulating clinical cases, analysing the removed choleliths and assessing diets of adult bearded dragons.